RADAR BULLETIN NO. 2 A

(RADTWO A)

THE TACTICAL USE OF RADAR IN AIRCRAFT

NAVY DEPARTMENT
OFFICE OF THE CHIEF OF NAVAL OPERATIONS

·

UNITED STATES
GOVERNMENT PRINTING OFFICE
WASHINGTON: 1946

NAVY DEPARTMENT
OFFICE OF THE CHIEF OF NAVAL OPERATIONS
WASHINGTON

LETTER OF PROMULGATION

11 December 1945.

1. This publication, THE TACTICAL USE OF RADAR IN AIRCRAFT, is issued for the use and guidance of the United States Fleet. Its principal purpose is to provide information concerning the physical and operational characteristics of airborne radar and allied electronics equipment.

2. This publication is effective upon receipt and supersedes Radar Bulletin No. 2 (RADTWO), all copies of which shall be destroyed by burning. No report of destruction is required.

This publication is CONFIDENTIAL [DECLASSIFIED] and shall be handled, stowed, and transported as prescribed in Article 76, U. S. Navy Regulations, 1920. When no longer required for use, it shall be destroyed by burning, no report of destruction being necessary.

4. This document contains information affecting the national defense, of the United States within the meaning of the Espionage Act, 50 U.S.C., 31 and 32, as amended. Its transmission or the revelation of its contents in any manner to an unauthorized person is prohibited by law.

5. While the classification of the publication necessarily CONFIDENTIAL commanding officers are urged to make certain that the book is available to all personnel whose duties require to the information contained therein.

6. This publication is under the cognizance of and is distributed by the Chief of Naval Operations.

C. M. Cooke, Jr.,DCNO (Operations).

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DISTRIBUTION LIST FOR
THE TACTICAL USE OF RADAR IN AIRCRAFT (Opnav 34-P-0801)

FOREWORD

The current effective USF tactical publications establish the necessary standard operating procedures for cooperative employment of naval units. These procedures are determined by evaluation of war experiences and the expected tasks to be assigned the various combinations of fleet units. By necessity these instruc-t ions are all inclusive and yet flexible so as to be applicable to the various tactical situations expected to be experienced by any specific fleet task organization.

Because the detailed employment of radar in all of its ramifications has become to an increasing extent inextricably a part of the successful execution of fleet tactics, USF 15 in its delineation of general tactical procedures involving radar, makes reference to the RAD series of official publications--supplementary publications which have been promulgated for the purpose of making available the current best practices in the arts of radar and electronics.

Of the several RAD publications now available or in the process of preparation, this publication, RADTWO A, concerns itself with the tactical use of radar and other allied electronic equipment in aircraft.

Used in aircraft, radar and other similar electronic devices provide the pilot fundamentally with information. It extends his sight under any condition of visibility, day or night; it furnishes quick and reliable navigation informal ion; it provides a better and more accurate bomb sight; and, in some cases, it controls the accuracy with which his guns may be fired.

During the preparation of RADTWO A, because of the scope of the field encompassed, there was manifest a tendency to misconstrue the meaning of its title, "The Tactical Use of Radar in Aircraft." In order to prevent future possible misunderstandings of its purpose and content, it is emphasized here that RADTWO A describes just what its title implies, the tactical use of radar in aircraft ... not the tactical use of radar-equipped aircraft. However, it has been attempted to indicate possible tactical uses of the electronic equipment without dictating the use of the aircraft. The fact that it is not always possible to divorce the use of the radar from the use of a radar-equipped plane is inescapable. Therefore, the information presented in RADTWO A is not to be considered as doctrine.

In contrast, however, to the seemingly confined viewpoint with regard to tactical use of radar in aircraft versus tactical use of radar-equipped aircraft, RADTWO A in its content has gone beyond a strict interpretation of its title by including information on equipments not essentially radar but certainly of an allied nature.

Such equipments as IFF, bombing attachments, beacons, loran, and electronic altimeters are not radar in the true sense of the word. Inclusion of descriptions of the use of such equipment in RADTWO A has been dictated by the fact that the theory and principles which underlie their function are closely allied to radar and, more important, in many cases radar-trained personnel are charged with their operation and use and should be cognizant of their complementary applications.

Since July of 1942, when the original RADTWO was published, certain early air-borne radar equipments have become obsolete because of technical advances. New air-borne radar systems and other electronic aids have been developed. In some equipments, simplification of control has gone ahead with increase in operating range; employment of higher radio frequencies has improved the resolution of targets as displayed on scopes; and developments of other electronic devices, some used in conjunction with radar, has made possible high- or low-altitude bombing, recognition and identification of friendly targets, beacon homing, and

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improved navigation in almost any condition of weather or visibility.

RADTWO A is issued, therefore, to provide nontechnical information concerning the tactical application and use of air-borne radar and associated electronic equipments currently (August 1945) in use in the fleet.

It is felt that a true evaluation of the capabilities and limitations of air-borne electronic equipments cannot be made without first having some general idea of how these systems function. Each of the parts of RADTWO A, therefore, is prefaced with a theory section for the purpose of presenting a brief, nontechnical explanation of the fundamental principles underlying the operation of the electronic gear described in that part.

Those sections describing the operating characteristics and employment of specific air-borne electronic equipments are presented not as the final word but as a compilation of the most recent, operationally proven information available on the subject.

In presenting the material contained in RADTWO A, it will be noted that there has been a studious attempt to concentrate on radar and other electronic equipment as such, without reference to particular aircraft in which such equipment has been customarily installed. This intent has been deliberate because it was felt that, with conditions and values in the art of

detection and ranging in a constant state of flux due to advances in design, engineering, and development; to associate a given piece of equipment with a given aircraft would have restricted RADTWO A's usefulness and limited its accuracy.

In the rapid development and production of electronics equipments designed for use in a multitude of types of naval aircraft, it was inevitable that during the period of time required for the preparation of this manual certain equipments would be superseded by improved equipments. For instance, the ASB series of air-borne radar equipments, although rapidly being replaced now by
AN/APS-3 and
AN/APS-4, was, from 1942 to early 1945,
the sole air-borne equipment upon which full reliance was placed, particularly with regard to radar installations in carrier-based aircraft.

For the sake of completeness of the historical or chronological development of air-borne rader, and because of the fact that several of the basic features of design and operation of the ASB system are still contained in other electronic aids (AN/APX-8, AN/APG-4, the technical information concerning the L-type scope display and the ASB series equipments is retained in this manual. The same line of reasoning has dictated the retention of descriptions of such equipments as AN/APA-16, AN/ARN-1, and the YJ radar beacon.